Hapalops antistis Ameghino
H. antistis Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 505.
The species is based on a skull, not figured, of which Ameghino says: the size is small, the molars are compressed from front to back, and gives the following measurements:
| Length of cranium from front of max. to occ. condyles | 140 mm. |
| Length of four post, molars | 27 mm. |
| Distance from front of max. to back of last molar | 48 mm. |
Octodontotherium Ameghino
Octodontotherium Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 656.
The genus is based on isolated teeth, each a mass of dentine surrounded by a thin layer of cement. The anterior tooth of the upper jaw is caniniform, the first molar ovoid in section, the last molar is bilobed, corresponding to Pseudolestodon. The first tooth of the lower jaw is also caniniform, but is two-faced as a result of wear. The intermediate upper and lower molars are rectangular prisms resembling those of Chlamdotherium.
Octodontotherium grandis Ameghino
- O. grandis Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 656.
- O. grandis Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 505.
In addition to the above, Ameghino simply gives the following measurements: